The flying wing idea was born in the early historical phase of the aircraft development with the goal to eliminate all external sections that do not participate actively in the lift production, hence minimizing drag, increasing lift capacity, and reducing the fuel consumption. Initially, the flying wing idea anticipated only wings with power plant without fuselage and tails. The elimination of fuselage required a certain increase of the chords and thickness of wings in order to provide for required payload accommodation. The increase of wing chords is increasing the airlifting surface area of wings. The increased surface area of wings that substitutes fuselage provides for either a higher lift capacity or ability to fly at lower attack angles, thereby resulting with lower profile, induced, and friction drag. The increased thickness of the wings in the payload area is resulting with increased relative thickness of airfoils and consequently increased profile drag.
The absence of fin with rudder did not cause serious repercussions relative to directional stability considering a low lateral aerodynamic reflection of wings. The yaw maneuver is controlled by differential drag on outer wings that is generated by spoilers or split elevons. A long distance between outer wings and aircraft gravity center in the lateral direction provides for a relatively satisfactory yaw maneuver.
However, the absence of the tailplane of “Tailess Flying Wing” concept is having significant negative effects on flight efficiency, as well as the maneuver and flight safety of such aircraft. The tailplane is capable to perform its functions successfully only if located at a great distance aft of the mean aerodynamic chord of the airlifting surface and aircraft gravity center. The classical wing forms without fuselage did not provide for such position of the tailplane, hence the classical flying wing concept has been developed mainly without tail. A significantly increased relative thickness of airfoils and the absence of the efficient pitch control functions of the tailplane have been the biggest constraints of the flying wing idea that prevented it from being widely implemented for mass air transportation despite great initial promises.
The first ideas as to how to practically realize the idea of flying wing into realistic projects for air transportation date back to early thirties of the 20th century. In the period of more than 80 years, these ideas have not been transformed into realistic projects except for sporadic pioneering attempts. The biggest accomplishment, by all means, has been achieved with B-2 aircraft, which was developed for specialized military purposes. However, this aircraft does not meet longitudinal dynamic stability requirements for civil aviation, while being prohibitively expensive, hence it does not represent a serious theoretical and practical base for development of the flying wing aircraft for civil mass air transportation. The latest project related to the flying wing concept for civil air transportation is the Boeing's BWB-450 baseline version that is based on the “Tailess Flying Wing” concept, which despite significant improvements relatively to the prior BWB generations did not resolve the key shortcomings and limitations when compared to the classical concept aircraft as follows:                It does not provide for a realistic position of gravity center with positive static margin due to unfavorable longitudinal distribution of payload, fuel, and airframe mass relatively to the neutral point, hence consequently being dynamically unstable in longitudinal direction.        It does not allow for the utilization of efficient airfoils with aft camber due to the fact that the neutral point and gravity center of the aircraft are significantly shifted in forward direction relatively to the mean aerodynamic chord. The longitudinal static stability of the BWB-450 aircraft in cruising conditions is possible to achieve by mostly using reflexed airfoils that have their air pressure center shifted in fore direction. Reflexed airfoils have a significantly lower efficiency at high subsonic and transonic speeds, thus considerably decreasing the initial advantages of the BWB concept.        It does not allow for the utilization of trailing edge flaps at low speeds during takeoff and landing, which in turn calls for a flight profile with high attack angles during landing, thus having significant negative repercussions on flight safety and ride quality.        It has a significantly lower longitudinal trim efficiency in cruising flight conditions due to a short distance of trim surfaces from the aircraft gravity center and the long mean aerodynamic chord of the airlifting surface.        It has a significantly lower level of longitudinal maneuverability especially at low flight speeds due to a short distance of maneuvering surfaces from the aircraft gravity center.        In addition, the problem related to high relative thickness of airfoils in the payload area was not satisfactorily resolved despite certain improvements relatively to the previous BWB generations. It remained significantly higher when compared to the relative thickness of airfoils that are used on the wings of classical concept aircraft. The relative thickness of airfoils in the payload area of the BWB concept is in the range between 10% and 15%, which is significantly increasing the compression and wave drag at flight speeds over Mach 0.8, thereby additionally decreasing the aircraft efficiency.        
The significant negative aspects in connection with the efficiency and flight safety of the “Tailess Flying Wing” concept, which are related to inability to provide for efficient pitch control without tailplane resulted with the emergence of various hybrid versions of the flying wing concept with the tailplane. The hybrid versions of the flying wing concept with tailplane had a goal to provide for a high aircraft aerodynamic efficiency and a satisfactory pitch control. A high efficiency of the aircraft implies as low airlifting surface area thereof as possible for a designed payload capacity, the lowest possible relative thickness and efficient shapes of airfoils, as well as a smooth aerodynamic shape in lateral direction across the span. A high pitch control efficiency of the tailplane requires the longest possible distance between the mean aerodynamic chord of the tailplane and the mean aerodynamic chord of the airlifting surface, as well as the longest possible distance between the tailplane and the aircraft gravity center.
U.S. Pat. Nos. 2,557,962; 2,616,639; 3,216,673; D198,610; 3,608,850; 3,630,471; 3,869,102; 6,098,922; 6,666,406B2, which refer to the hybrid versions of the flying wing with tailplane represent attempts to convert the classical forms of the aircraft with tailplane into hybrid versions of the flying wing by completely or partially reshaping the fuselage into airlifting surfaces. The tailplane is joined the fuselage lifting body either directly or by means of extended nacelles or vertical tails. The positive effects are reflected in the increase of aircraft payload capacity for the approximately same external dimensions, which is one of the goals of the flying wing idea. However, the following are the negative effects of designs that were presented in the above patents:                The application of thick airfoils due to short chords in the payload area, thereby reducing the aerodynamic efficiency at higher subsonic speeds.        Rough aerodynamic transitions in lateral direction between the airlifting surface of fuselage and the airlifting surface of outer wings, thereby drastically increasing the interference drag and resulting with more complex airframe configurations from the manufacturing point.        All aerodynamic shapes from the prior art listed above are configured for low subsonic speeds only, which limits their application range.        
One of the most recent attempts to affirm the flying wing idea for highly efficient high-subsonic and transonic civil air transportation is reflected in U.S. Pat. No. 6,923,403 named “Tailed Flying Wing Aircraft” where smoothly integrated trapezoidal outer wings with elongated central airlifting section create a unique aerodynamically efficient airlifting body by way of transition sections. A significant sweepback angle of the central section leading edge, as well as a semi-elliptical convexly elongated trailing edge in the aft direction have considerably extended the chord lengths of the central section and provided for payload disposal within airlifting surface that is defined with significantly thinner airfoils when compared to BWB's tailess concept aircraft. On the other hand, the trailing edge of the “Tailed Flying Wing Aircraft”, which is significantly elliptically and convexly elongated in aft direction allowed for the tailplane to be positioned significantly aft of the mean aerodynamic chord of airlifting surface, thus shifting the neutral point of the aircraft in aft direction, hence allowing for the realistic position of aircraft gravity center in front of the neutral point, thereby providing for required longitudinal dynamic stability of civil aircraft, which was impossible to achieve with “Tailess Flying Wing” concepts. Additionally, the convexly elliptical form of the rear portion of the central section of “Tailed Flying Wing Aircraft” provided for almost elliptical span wise lift distribution, hence generating a low induced drag.
However, a more detailed and encompassing aerodynamic analyses of this concept showed that the longitudinal position of the tailplane, which depends on the semi-elliptical form of the central section trailing edge was not sufficiently shifted in aft direction to provide for the application of efficient supercritical airfoils in the payload area including the inability to deploy trailing edge flaps during landing and take-off for the same reason. The further elongation of semi-elliptical trailing edge of the central section with intention to additionally shift the tailplane in the aft direction would inefficiently increase the area of the airlifting surface, thereby increasing the friction drag and significantly decreasing the positive effects gained by shifting the tailplane in aft direction. This clearly led to the conclusion that it was necessary to find a more efficient form for the central section of the airlifting surface to which the tailplane is joined.